#include<stdio.h>
int main()
{
    char arr[8000];
    long long c = 0, ch = 0, chn = 0;
    scanf("%s", arr);
    char* p = arr;
    while (*p)
    {
        if (*p == 'C')
            c++;
        else if (*p == 'H')
            ch += c;
        else if (*p == 'N')
            chn += ch;
        p++;
    }
    printf("%lld", chn);
    return 0;
}